From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754308Ab3LQWid (ORCPT ); Tue, 17 Dec 2013 17:38:33 -0500 Received: from mail-by2lp0240.outbound.protection.outlook.com ([207.46.163.240]:39397 "EHLO na01-by2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752003Ab3LQWic (ORCPT ); Tue, 17 Dec 2013 17:38:32 -0500 Message-ID: <1387319904.10013.482.camel@snotra.buserror.net> Subject: Re: [PATCH v2] powerpc 8xx: Loading kernels over 8Mbytes without CONFIG_PIN_TLB From: Scott Wood To: leroy christophe CC: Benjamin Herrenschmidt , Paul Mackerras , , Date: Tue, 17 Dec 2013 16:38:24 -0600 In-Reply-To: <52AFE70D.70407@c-s.fr> References: <20131210112945.E4E311A2BF3@localhost.localdomain> <1386714253.10013.123.camel@snotra.buserror.net> <52A79E31.9070304@c-s.fr> <1386717537.10013.150.camel@snotra.buserror.net> <52A7A58F.8090705@c-s.fr> <1387234621.10013.408.camel@snotra.buserror.net> <52AFE70D.70407@c-s.fr> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.4-0ubuntu1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Originating-IP: [2601:2:5800:3f7:12bf:48ff:fe84:c9a0] X-ClientProxiedBy: BL2PR02CA004.namprd02.prod.outlook.com (10.141.66.14) To DM2PR03MB398.namprd03.prod.outlook.com (10.141.84.140) X-Forefront-PRVS: 006339698F X-Forefront-Antispam-Report: SFV:NSPM;SFS:(10009001)(51704005)(479174003)(189002)(199002)(377424004)(24454002)(23676002)(50986001)(90146001)(42186004)(53806001)(85306002)(89996001)(56816005)(80976001)(51856001)(76482001)(49866001)(79102001)(63696002)(83322001)(81816001)(47776003)(47736001)(4396001)(65816001)(47976001)(81686001)(69226001)(46102001)(87976001)(59766001)(88136002)(85852003)(77096001)(87266001)(77982001)(54316002)(87286001)(74366001)(56776001)(76786001)(83072002)(80022001)(81542001)(31966008)(74502001)(74662001)(47446002)(81342001)(74706001)(50226001)(76796001)(77156001)(50466002)(74876001)(33646001)(62966002)(3826001);DIR:OUT;SFP:1101;SCL:1;SRVR:DM2PR03MB398;H:[IPv6:2601:2:5800:3f7:12bf:48ff:fe84:c9a0];CLIP:2601:2:5800:3f7:12bf:48ff:fe84:c9a0;FPR:;RD:InfoNoRecords;MX:1;A:1;LANG:en; X-OriginatorOrg: freescale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2013-12-17 at 06:54 +0100, leroy christophe wrote: > Le 16/12/2013 23:57, Scott Wood a écrit : > > On Wed, 2013-12-11 at 00:36 +0100, leroy christophe wrote: > >> Le 11/12/2013 00:18, Scott Wood a écrit : > >>> There wasn't previously an ifdef specifically around the setting of > >>> SPRN_MD_CTR. That's new. There was an ifdef around the entire block, > >>> which has gone away because you are now trying to map more than 8M > >>> regardless of CONFIG_PIN_TLB, but that has nothing to do with whether > >>> there should be an ifdef around SPRN_MD_CTR. > >>> > >>> > >> Euh, ok, but then we have to fix it in the whole function, not only in > >> this block. Do you think it is worth doing it ? > > Fix what in the whole function? I was asking what harm there would be > > if you just remove all the CONFIG_PIN_TLB ifdefs except around the > > actual RSV4I setting -- do we really care what value goes in MD_CTR for > > the non-pinned case, as long as it's different for each entry? > > > > > MD_CTR is decremented after each entry added. > However, the function populates entry 28, then 29, then 30, then 31. At > the end MD_CTR has then value 30, ready to overide entry 30 then 29 then > 28 then 27 ..... > > So I will remove all the CONFIG_PIN_TLB, but I'll also have to fix the > value set in MD_CTR to start from 31, won't I ? OK, so the answer is that we rely on autodecrement avoiding entries over 28 in the CONFIG_PIN_TLB case. Leave the ifdefs, then. > Do you have any comment/recommendation on my tentative v3 patch where I > have tried to implement based on the use of r7 as you recommended ? I haven't reviewed it yet. -Scott